58 Introditction to Aniuial Morphology. 



which are protruded at all sides (Amceba), or at one side only 

 (A.limax), or radiating from one end (Petalopus). There 

 may be a delicate test, but not sufficient to prevent the 

 alterations in shape, incompletely (Pseudochlamys) or com- 

 pletely enclosing the body (Corycia), or a hyaline coat pene- 

 trable by the pseudopodia, after the retraction of which the 

 openings disappear (Amphizonella). In Pamphagus, lobose 

 pseudopodia protrude at one end, while in Diplophrys they 

 are as tufts at each end. Boderia is a giant Amoeba, repro- 

 ducing somewhat as Magosphaera by pseudo-navicellar, but 

 non-ciliated, bodies {T. S. Wright). Podostoma has flagelli- 

 form pseudopodia. 



Fam. 2. Arcellidae — (Fig. 3). Test firm, one-celled, it may 

 be ovoid, coated with fine agglutinated sand-grains (Difflugia), 

 with a down-directed mouth, or hyaline, flattened, facetted, often 

 striated siliceous (?), with branched p.. 



pseudopodia, and many contractile 

 vesicles (Arcella). Euglypha has a 

 regularly sculptured chitinoid test 

 with depressions. Cyphoderia is 

 spinose. Amphitrema has an opening 

 at each end from which pseudopodia 

 project. Echinopyxis sends its pseu- 

 dopodia through short tubular pro- 

 cesses of its test. PlatoumParvum. 



Fam. 3. Actinophryidse — Minute, spheroidal, freshwater, 

 slow-moving animals, with constant, radiant, ectosarcal pseu- 

 dopodia, which often unite at their tips. The contractile 

 vesicle is near the surface, and when distended appears as a 

 bubble. The ectosarc is marked by polygonal meshes of 

 granular protoplasmic threads enclosing vacuoles. They 

 multiply by fission. The globular forms are named Actino- 

 phr}^s, if stalked, Podophrya,* if depressed with marginal 

 pseudopodia, Trichodiscus. Clathrulina has a globularf 

 stalked shell of lattice-work, through whose holes the pseudo- 

 podia protrude. 



* If the pedicle be branched, Dendrosoma, 

 t Sihceous, Greef. 



